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Sedlák F, Kvasnička A, Marešová B, Brumarová R, Dobešová D, Dostálová K, Šrámková K, Pehr M, Šácha P, Friedecký D, Konvalinka J. Parallel Metabolomics and Lipidomics of a PSMA/GCPII Deficient Mouse Model Reveal Alteration of NAAG Levels and Brain Lipid Composition. ACS Chem Neurosci 2024; 15:1342-1355. [PMID: 38377674 PMCID: PMC10995945 DOI: 10.1021/acschemneuro.3c00494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 01/10/2024] [Accepted: 02/05/2024] [Indexed: 02/22/2024] Open
Abstract
Glutamate carboxypeptidase II (GCPII, also known as PSMA or FOLH1) is responsible for the cleavage of N-acetyl-aspartyl-glutamate (NAAG) to N-acetyl-aspartate and glutamate in the central nervous system and facilitates the intestinal absorption of folate by processing dietary folyl-poly-γ-glutamate in the small intestine. The physiological function of GCPII in other organs like kidneys is still not known. GCPII inhibitors are neuroprotective in various conditions (e.g., ischemic brain injury) in vivo; however, their utilization as potential drug candidates has not been investigated in regard to not yet known GCPII activities. To explore the GCPII role and possible side effects of GCPII inhibitors, we performed parallel metabolomic and lipidomic analysis of the cerebrospinal fluid (CSF), urine, plasma, and brain tissue of mice with varying degrees of GCPII deficiency (fully deficient in Folh1, -/-; one allele deficient in Folh1, +/-; and wild type, +/+). Multivariate analysis of metabolites showed no significant differences between wild-type and GCPII-deficient mice (except for NAAG), although changes were observed between the sex and age. NAAG levels were statistically significantly increased in the CSF, urine, and plasma of GCPII-deficient mice. However, no difference in NAAG concentrations was found in the whole brain lysate likely because GCPII, as an extracellular enzyme, can affect only extracellular and not intracellular NAAG concentrations. Regarding the lipidome, the most pronounced genotype-linked changes were found in the brain tissue. In brains of GCPII-deficient mice, we observed statistically significant enrichment in phosphatidylcholine-based lipids and reduction of sphingolipids and phosphatidylethanolamine plasmalogens. We hypothesize that the alteration of the NAA-NAAG axis by absent GCPII activity affected myelin composition. In summary, the absence of GCPII and thus similarly its inhibition do not have detrimental effects on metabolism, with just minor changes in the brain lipidome.
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Affiliation(s)
- František Sedlák
- Institute
of Organic Chemistry and Biochemistry, Czech
Academy of Sciences, Prague 6 166 10, Czechia
- Institute
of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague 2 110 01, Czechia
- First
Department of Internal Medicine - Hematology, Charles University General Hospital in Prague, Prague 110 01, Czechia
| | - Aleš Kvasnička
- Laboratory
for Inherited Metabolic Disorders, Department of Clinical Biochemistry, University Hospital Olomouc, and Faculty of Medicine
and Dentistry, Palacký University Olomouc, Zdravotníku° 248/7, Olomouc 779 00, Czechia
| | - Barbora Marešová
- Institute
of Organic Chemistry and Biochemistry, Czech
Academy of Sciences, Prague 6 166 10, Czechia
- Institute
of Biochemistry and Experimental Oncology, First Faculty of Medicine, Charles University, Prague 2 110 01, Czechia
| | - Radana Brumarová
- Laboratory
for Inherited Metabolic Disorders, Department of Clinical Biochemistry, University Hospital Olomouc, and Faculty of Medicine
and Dentistry, Palacký University Olomouc, Zdravotníku° 248/7, Olomouc 779 00, Czechia
| | - Dana Dobešová
- Laboratory
for Inherited Metabolic Disorders, Department of Clinical Biochemistry, University Hospital Olomouc, and Faculty of Medicine
and Dentistry, Palacký University Olomouc, Zdravotníku° 248/7, Olomouc 779 00, Czechia
| | - Kateřina Dostálová
- Laboratory
for Inherited Metabolic Disorders, Department of Clinical Biochemistry, University Hospital Olomouc, and Faculty of Medicine
and Dentistry, Palacký University Olomouc, Zdravotníku° 248/7, Olomouc 779 00, Czechia
| | - Karolína Šrámková
- Institute
of Organic Chemistry and Biochemistry, Czech
Academy of Sciences, Prague 6 166 10, Czechia
| | - Martin Pehr
- Institute
of Organic Chemistry and Biochemistry, Czech
Academy of Sciences, Prague 6 166 10, Czechia
- Third
Department of Medicine − Department of Endocrinology and Metabolism
of the first Faculty of Medicine and General University Hospital in
Prague, Charles University, Prague 110 01, Czechia
| | - Pavel Šácha
- Institute
of Organic Chemistry and Biochemistry, Czech
Academy of Sciences, Prague 6 166 10, Czechia
| | - David Friedecký
- Laboratory
for Inherited Metabolic Disorders, Department of Clinical Biochemistry, University Hospital Olomouc, and Faculty of Medicine
and Dentistry, Palacký University Olomouc, Zdravotníku° 248/7, Olomouc 779 00, Czechia
| | - Jan Konvalinka
- Institute
of Organic Chemistry and Biochemistry, Czech
Academy of Sciences, Prague 6 166 10, Czechia
- Department
of Biochemistry, Faculty of Science, Charles
University, Hlavova 8, Prague 128 00, Czechia
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Luo H, Lao L, Au KS, Northrup H, He X, Forget D, Gauthier MS, Coulombe B, Bourdeau I, Shi W, Gagliardi L, Fragoso MCBV, Peng J, Wu J. ARMC5 controls the degradation of most Pol II subunits, and ARMC5 mutation increases neural tube defect risks in mice and humans. Genome Biol 2024; 25:19. [PMID: 38225631 PMCID: PMC10789052 DOI: 10.1186/s13059-023-03147-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 12/18/2023] [Indexed: 01/17/2024] Open
Abstract
BACKGROUND Neural tube defects (NTDs) are caused by genetic and environmental factors. ARMC5 is part of a novel ubiquitin ligase specific for POLR2A, the largest subunit of RNA polymerase II (Pol II). RESULTS We find that ARMC5 knockout mice have increased incidence of NTDs, such as spina bifida and exencephaly. Surprisingly, the absence of ARMC5 causes the accumulation of not only POLR2A but also most of the other 11 Pol II subunits, indicating that the degradation of the whole Pol II complex is compromised. The enlarged Pol II pool does not lead to generalized Pol II stalling or a generalized decrease in mRNA transcription. In neural progenitor cells, ARMC5 knockout only dysregulates 106 genes, some of which are known to be involved in neural tube development. FOLH1, critical in folate uptake and hence neural tube development, is downregulated in the knockout intestine. We also identify nine deleterious mutations in the ARMC5 gene in 511 patients with myelomeningocele, a severe form of spina bifida. These mutations impair the interaction between ARMC5 and Pol II and reduce Pol II ubiquitination. CONCLUSIONS Mutations in ARMC5 increase the risk of NTDs in mice and humans. ARMC5 is part of an E3 controlling the degradation of all 12 subunits of Pol II under physiological conditions. The Pol II pool size might have effects on NTD pathogenesis, and some of the effects might be via the downregulation of FOLH1. Additional mechanistic work is needed to establish the causal effect of the findings on NTD pathogenesis.
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Affiliation(s)
- Hongyu Luo
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada.
| | - Linjiang Lao
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Kit Sing Au
- Department of Pediatrics, McGovern Medical School at the University of Texas Health Science Center at Houston (UTHealth) and Children's Memorial Hermann Hospital, Houston, TX, USA
| | - Hope Northrup
- Department of Pediatrics, McGovern Medical School at the University of Texas Health Science Center at Houston (UTHealth) and Children's Memorial Hermann Hospital, Houston, TX, USA
| | - Xiao He
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Diane Forget
- Department of Translational Proteomics, Institut de Recherches Cliniques de Montréal, Montreal, QC, Canada
| | - Marie-Soleil Gauthier
- Department of Translational Proteomics, Institut de Recherches Cliniques de Montréal, Montreal, QC, Canada
| | - Benoit Coulombe
- Department of Translational Proteomics, Institut de Recherches Cliniques de Montréal, Montreal, QC, Canada
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montreal, QC, Canada
| | - Isabelle Bourdeau
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada
- Division of Endocrinology, CHUM, Montreal, QC, Canada
- Department of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Wei Shi
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Lucia Gagliardi
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia
- Department of Genetics and Molecular Pathology, SA Pathology, Adelaide, Australia
- Endocrine and Diabetes Unit, Queen Elizabeth Hospital, Adelaide, Australia
| | - Maria Candida Barisson Villares Fragoso
- Unidade de Suprarrenal Disciplina de Endocrinologia E Metabologia, Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Junzheng Peng
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Jiangping Wu
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada.
- Department of Medicine, Université de Montréal, Montreal, QC, Canada.
- Division of Nephrology, CHUM, Montreal, QC, Canada.
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Hyväkkä A, Virtanen V, Kemppainen J, Grönroos TJ, Minn H, Sundvall M. More Than Meets the Eye: Scientific Rationale behind Molecular Imaging and Therapeutic Targeting of Prostate-Specific Membrane Antigen (PSMA) in Metastatic Prostate Cancer and Beyond. Cancers (Basel) 2021; 13:cancers13092244. [PMID: 34067046 PMCID: PMC8125679 DOI: 10.3390/cancers13092244] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 04/30/2021] [Accepted: 05/02/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Prostate-specific membrane antigen (PSMA) is a transmembrane protein that is overexpressed in prostate cancer and correlates with the aggressiveness of the disease. PSMA is a promising target for imaging and therapeutics in prostate cancer patients validated in prospective trials. However, the role of PSMA in prostate cancer progression is poorly understood. In this review, we discuss the biology and scientific rationale behind the use of PSMA and other targets in the detection and theranostics of metastatic prostate cancer. Abstract Prostate cancer is the second most common cancer type in men globally. Although the prognosis for localized prostate cancer is good, no curative treatments are available for metastatic disease. Better diagnostic methods could help target therapies and improve the outcome. Prostate-specific membrane antigen (PSMA) is a transmembrane glycoprotein that is overexpressed on malignant prostate tumor cells and correlates with the aggressiveness of the disease. PSMA is a clinically validated target for positron emission tomography (PET) imaging-based diagnostics in prostate cancer, and during recent years several therapeutics have been developed based on PSMA expression and activity. The expression of PSMA in prostate cancer can be very heterogeneous and some metastases are negative for PSMA. Determinants that dictate clinical responses to PSMA-targeting therapeutics are not well known. Moreover, it is not clear how to manipulate PSMA expression for therapeutic purposes and develop rational treatment combinations. A deeper understanding of the biology behind the use of PSMA would help the development of theranostics with radiolabeled compounds and other PSMA-based therapeutic approaches. Along with PSMA several other targets have also been evaluated or are currently under investigation in preclinical or clinical settings in prostate cancer. Here we critically elaborate the biology and scientific rationale behind the use of PSMA and other targets in the detection and therapeutic targeting of metastatic prostate cancer.
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Affiliation(s)
- Anniina Hyväkkä
- Institute of Biomedicine, Cancer Research Unit, FICAN West Cancer Center Laboratory, University of Turku and Turku University Hospital, FI-20520 Turku, Finland; (A.H.); (V.V.)
| | - Verneri Virtanen
- Institute of Biomedicine, Cancer Research Unit, FICAN West Cancer Center Laboratory, University of Turku and Turku University Hospital, FI-20520 Turku, Finland; (A.H.); (V.V.)
- Turku Doctoral Programme of Molecular Medicine (TuDMM), University of Turku, FI-20520 Turku, Finland
| | - Jukka Kemppainen
- Turku PET Centre, University of Turku, FI-20521 Turku, Finland;
- Department of Clinical Physiology and Nuclear Medicine, Turku University Hospital, FI-20521 Turku, Finland
- Docrates Cancer Center, FI-00180 Helsinki, Finland
| | - Tove J. Grönroos
- Preclinical Imaging Laboratory, Turku PET Centre, University of Turku, FI-20520 Turku, Finland;
| | - Heikki Minn
- Department of Oncology, FICAN West Cancer Center, University of Turku and Turku University Hospital, FI-20521 Turku, Finland;
| | - Maria Sundvall
- Institute of Biomedicine, Cancer Research Unit, FICAN West Cancer Center Laboratory, University of Turku and Turku University Hospital, FI-20520 Turku, Finland; (A.H.); (V.V.)
- Department of Oncology, FICAN West Cancer Center, University of Turku and Turku University Hospital, FI-20521 Turku, Finland;
- Correspondence:
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Vorlová B, Sedlák F, Kašpárek P, Šrámková K, Malý M, Zámečník J, Šácha P, Konvalinka J. A novel PSMA/GCPII-deficient mouse model shows enlarged seminal vesicles upon aging. Prostate 2019; 79:126-139. [PMID: 30256431 DOI: 10.1002/pros.23717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 08/21/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND Prostate-specific membrane antigen (PSMA), also known as glutamate carboxypeptidase II (GCPII), is an important diagnostic and therapeutic target in prostate cancer. PSMA/GCPII is also expressed in many healthy tissues, but its function has only been established in the brain and small intestine. Several research groups have attempted to produce PSMA/GCPII-deficient mice to study the physiological role of PSMA/GCPII in detail. The outcomes of these studies differ dramatically, ranging from embryonic lethality to production of viable PSMA/GCPII-deficient mice without any obvious phenotype. METHODS We produced PSMA/GCPII-deficient mice (hereafter also referred as Folh1-/- mice) by TALEN-mediated mutagenesis on a C57BL/6NCrl background. Using Western blot and an enzyme activity assay, we confirmed the absence of PSMA/GCPII in our Folh1-/- mice. We performed anatomical and histopathological examination of selected tissues with a focus on urogenital system. We also examined the PSMA/GCPII expression profile within the mouse urogenital system using an enzyme activity assay and confirmed the presence of PSMA/GCPII in selected tissues by immunohistochemistry. RESULTS Our Folh1-/- mice are viable, breed normally, and do not show any obvious phenotype. Nevertheless, aged Folh1-/- mice of 69-72 weeks exhibit seminal vesicle dilation, which is caused by accumulation of luminal fluid. This phenotype was also observed in Folh1+/- mice; the overall difference between our three cohorts (Folh1-/- , Folh1+/- , and Folh1+/+ ) was highly significant (P < 0.002). Of all studied tissues of the mouse urogenital system, only the epididymis appeared to have a physiologically relevant level of PSMA/GCPII expression. Additional experiments demonstrated that PSMA/GCPII is also present in the human epididymis. CONCLUSIONS In this study, we provide the first evidence characterizing the reproductive tissue phenotype of PSMA/GCPII-deficient mice. These findings will help lay the groundwork for future studies to reveal PSMA/GCPII function in human reproduction.
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Affiliation(s)
- Barbora Vorlová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
- First Faculty of Medicine, Charles University, Prague 2, Czech Republic
| | - František Sedlák
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
- First Faculty of Medicine, Charles University, Prague 2, Czech Republic
- Faculty of Science, Department of Genetics and Microbiology, Charles University, Prague 2, Czech Republic
| | - Petr Kašpárek
- Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic
- Czech Centre for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Karolína Šrámková
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
| | - Marek Malý
- National Institute of Public Health, Prague 10, Czech Republic
| | - Josef Zámečník
- Department of Pathology and Molecular Medicine, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague 5, Czech Republic
| | - Pavel Šácha
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
| | - Jan Konvalinka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, Czech Republic
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De Sanctis C, Bellenchi GC, Viggiano D. A meta-analytic approach to genes that are associated with impaired and elevated spatial memory performance. Psychiatry Res 2018; 261:508-516. [PMID: 29395873 DOI: 10.1016/j.psychres.2018.01.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 01/15/2018] [Accepted: 01/15/2018] [Indexed: 12/11/2022]
Abstract
Spatial memory deficits are a common hallmark of psychiatric conditions, possibly due to a genetic predisposition. Thus, unravelling the relationship between genes and memory might suggest novel therapeutic targets and pathogenetic pathways. Genetic deletions are known to lead to memory deficits (post-deletion "forgetfulness" genes, PDF), or, in few instances to improve spatial memory (post-deletion "hypermnesic" genes, PDH). To assess this topic, we performed a meta-analytic approach on memory behavior in knock-out mice. We screened 300 studies from PubMed and retrieved 87 genes tested for possible effects on spatial memory. This database was crossed with the Allen Brain Atlas (brain distribution) and the Enrichr (gene function) databases. The results show that PDF genes have higher expression level in several ventral brain structures, particularly the encephalic trunk and in the hypothalamus. Moreover, part of these genes are implicated in synaptic functions. Conversely, the PDH genes are associated to G-protein coupled receptors downstream signalling. Some candidate drugs were also found to interfere with some of the PDH genes, further suggesting that this approach might help in identifying drugs to improve memory performance in psychiatric conditions.
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Affiliation(s)
- Claudia De Sanctis
- IRCCS Neuromed, Pozzilli, IS 86077, Italy; Department of Medicine and Health Sciences, University of Molise, Via De Sanctis, Campobasso 86100, Italy
| | | | - Davide Viggiano
- Department of Medicine and Health Sciences, University of Molise, Via De Sanctis, Campobasso 86100, Italy.
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Knedlík T, Vorlová B, Navrátil V, Tykvart J, Sedlák F, Vaculín Š, Franěk M, Šácha P, Konvalinka J. Mouse glutamate carboxypeptidase II (GCPII) has a similar enzyme activity and inhibition profile but a different tissue distribution to human GCPII. FEBS Open Bio 2017; 7:1362-1378. [PMID: 28904865 PMCID: PMC5586342 DOI: 10.1002/2211-5463.12276] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/23/2017] [Accepted: 07/19/2017] [Indexed: 11/09/2022] Open
Abstract
Glutamate carboxypeptidase II (GCPII), also known as prostate-specific membrane antigen (PSMA) or folate hydrolase, is a metallopeptidase expressed predominantly in the human brain and prostate. GCPII expression is considerably increased in prostate carcinoma, and the enzyme also participates in glutamate excitotoxicity in the brain. Therefore, GCPII represents an important diagnostic marker of prostate cancer progression and a putative target for the treatment of both prostate cancer and neuronal disorders associated with glutamate excitotoxicity. For the development of novel therapeutics, mouse models are widely used. However, although mouse GCPII activity has been characterized, a detailed comparison of the enzymatic activity and tissue distribution of the mouse and human GCPII orthologs remains lacking. In this study, we prepared extracellular mouse GCPII and compared it with human GCPII. We found that mouse GCPII possesses lower catalytic efficiency but similar substrate specificity compared with the human protein. Using a panel of GCPII inhibitors, we discovered that inhibition constants are generally similar for mouse and human GCPII. Furthermore, we observed highest expression of GCPII protein in the mouse kidney, brain, and salivary glands. Importantly, we did not detect GCPII in the mouse prostate. Our data suggest that the differences in enzymatic activity and inhibition profile are rather small; therefore, mouse GCPII can approximate human GCPII in drug development and testing. On the other hand, significant differences in GCPII tissue expression must be taken into account when developing novel GCPII-based anticancer and therapeutic methods, including targeted anticancer drug delivery systems, and when using mice as a model organism.
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Affiliation(s)
- Tomáš Knedlík
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague Czech Republic.,Department of Biochemistry Faculty of Science Charles University Prague Czech Republic
| | - Barbora Vorlová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague Czech Republic.,First Faculty of Medicine Charles University Prague Czech Republic
| | - Václav Navrátil
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague Czech Republic.,Department of Biochemistry Faculty of Science Charles University Prague Czech Republic
| | - Jan Tykvart
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague Czech Republic.,Department of Biochemistry Faculty of Science Charles University Prague Czech Republic.,Present address: Donnelly Centre for Cellular and Biomolecular Research University of Toronto Toronto ON Canada
| | - František Sedlák
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague Czech Republic.,First Faculty of Medicine Charles University Prague Czech Republic.,Department of Genetics and Microbiology Faculty of Science Charles University Prague Czech Republic
| | - Šimon Vaculín
- Department of Normal, Pathological and Clinical Physiology Third Faculty of Medicine Charles University Prague Czech Republic
| | - Miloslav Franěk
- Department of Normal, Pathological and Clinical Physiology Third Faculty of Medicine Charles University Prague Czech Republic
| | - Pavel Šácha
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague Czech Republic
| | - Jan Konvalinka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague Czech Republic.,Department of Biochemistry Faculty of Science Charles University Prague Czech Republic
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Khacho P, Wang B, Bergeron R. The Good and Bad Sides of NAAG. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 76:311-49. [PMID: 27288081 DOI: 10.1016/bs.apha.2016.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Why has such a small peptide been the source of controversy in neuroscience over the last 5 decades? Is N-acetyl-aspartyl-glutamate (NAAG) a neurotransmitter? Is NAAG located in neuronal tissue or in astrocytes? Is NAAG involved in neuropsychiatric and neurodegenerative disorders? Is NAAG therapeutically beneficial in the treatment of stroke or in initiating cascades of events leading to psychosis? After many years of intense research there is no clear consensus within the scientific community on how NAAG behaves in the brain. One of the major controversies about NAAG is its physiological action at N-methyl-d-aspartate (NMDA) receptors. While some researchers strongly argue that NAAG acts as a weak agonist at NMDA receptors, others have suggested that NAAG could behave as a potent antagonist. Published data from our laboratory demonstrate that the effect of NAAG on NMDA receptors could be influenced by a number of factors including the subcellular localization and subunit composition of NMDA receptors, as well as protons. In this chapter, we will summarize the knowledge of the literature on NAAG, however, we will place emphasis on our recently published data. More specifically, we have reported interesting findings on the effects of NAAG on NMDA receptors at synaptic and extrasynaptic sites using a pharmacological paradigm to distinguish the two populations of NMDA receptors. Additionally, we have evaluated the role of NAAG on GluN2A- and GluN2B-containing NMDA receptors using a HEK293 cell recombinant system. Finally, we have studied the effects of NAAG on GluN2A- and GluN2B-containing NMDA receptors in different extracellular pH conditions. We believe that our findings could potentially resolve some aspects of the debate regarding the role of NAAG at NMDA receptors.
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Affiliation(s)
- P Khacho
- University of Ottawa, Ottawa, ON, Canada
| | - B Wang
- University of Ottawa, Ottawa, ON, Canada
| | - R Bergeron
- University of Ottawa, Ottawa, ON, Canada; Ottawa Hospital Research Institute, Ottawa, ON, Canada.
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Jansen RS, Mahakena S, de Haas M, Borst P, van de Wetering K. ATP-binding Cassette Subfamily C Member 5 (ABCC5) Functions as an Efflux Transporter of Glutamate Conjugates and Analogs. J Biol Chem 2015; 290:30429-40. [PMID: 26515061 DOI: 10.1074/jbc.m115.692103] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Indexed: 01/12/2023] Open
Abstract
The ubiquitous efflux transporter ABCC5 (ATP-binding cassette subfamily C member 5) is present at high levels in the blood-brain barrier, neurons, and glia, but its in vivo substrates and function are not known. Using untargeted metabolomic screens, we show that Abcc5(-/-) mice accumulate endogenous glutamate conjugates in several tissues, but brain in particular. The abundant neurotransmitter N-acetylaspartylglutamate was 2.4-fold higher in Abcc5(-/-) brain. The metabolites that accumulated in Abcc5(-/-) tissues were depleted in cultured cells that overexpressed human ABCC5. In a vesicular membrane transport assay, ABCC5 also transported exogenous glutamate analogs, like the classic excitotoxic neurotoxins kainic acid, domoic acid, and NMDA; the therapeutic glutamate analog ZJ43; and, as previously shown, the anti-cancer drug methotrexate. Glutamate conjugates and analogs are of physiological relevance because they can affect the function of glutamate, the principal excitatory neurotransmitter in the brain. After CO2 asphyxiation, several immediate early genes were expressed at lower levels in Abcc5(-/-) brains than in wild type brains, suggesting altered glutamate signaling. Our results show that ABCC5 is a general glutamate conjugate and analog transporter that affects the disposition of endogenous metabolites, toxins, and drugs.
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Affiliation(s)
- Robert S Jansen
- From the Division of Molecular Oncology, Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
| | - Sunny Mahakena
- From the Division of Molecular Oncology, Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
| | - Marcel de Haas
- From the Division of Molecular Oncology, Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
| | - Piet Borst
- From the Division of Molecular Oncology, Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
| | - Koen van de Wetering
- From the Division of Molecular Oncology, Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
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Gao Y, Xu S, Cui Z, Zhang M, Lin Y, Cai L, Wang Z, Luo X, Zheng Y, Wang Y, Luo Q, Jiang J, Neale JH, Zhong C. Mice lacking glutamate carboxypeptidase II develop normally, but are less susceptible to traumatic brain injury. J Neurochem 2015; 134:340-53. [PMID: 25872793 DOI: 10.1111/jnc.13123] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 04/04/2015] [Accepted: 04/08/2015] [Indexed: 11/26/2022]
Affiliation(s)
- Yang Gao
- Department of Neurosurgery; Ren Ji Hospital; School of Medicine; Shanghai Jiao Tong University; Shanghai China
| | - Siyi Xu
- Department of Neurosurgery; Ren Ji Hospital; School of Medicine; Shanghai Jiao Tong University; Shanghai China
| | - Zhenwen Cui
- Department of Neurosurgery; Ren Ji Hospital; School of Medicine; Shanghai Jiao Tong University; Shanghai China
| | - Mingkun Zhang
- Department of Neurosurgery; Ren Ji Hospital; School of Medicine; Shanghai Jiao Tong University; Shanghai China
| | - Yingying Lin
- Department of Neurosurgery; Ren Ji Hospital; School of Medicine; Shanghai Jiao Tong University; Shanghai China
| | - Lei Cai
- Shanghai Research Center for Model Organisms; Shanghai China
| | - Zhugang Wang
- Shanghai Research Center for Model Organisms; Shanghai China
| | - Xingguang Luo
- Department of Psychiatry; Yale University School of Medicine; West Haven Connecticut USA
| | - Yan Zheng
- Department of Neurosurgery; Ren Ji Hospital; School of Medicine; Shanghai Jiao Tong University; Shanghai China
| | - Yong Wang
- Department of Neurosurgery; Ren Ji Hospital; School of Medicine; Shanghai Jiao Tong University; Shanghai China
| | - Qizhong Luo
- Department of Neurosurgery; Ren Ji Hospital; School of Medicine; Shanghai Jiao Tong University; Shanghai China
| | - Jiyao Jiang
- Department of Neurosurgery; Ren Ji Hospital; School of Medicine; Shanghai Jiao Tong University; Shanghai China
| | - Joseph H. Neale
- Department of Biology; Georgetown University; Washington DC USA
| | - Chunlong Zhong
- Department of Neurosurgery; Ren Ji Hospital; School of Medicine; Shanghai Jiao Tong University; Shanghai China
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Genetically modified mice related to schizophrenia and other psychoses: seeking phenotypic insights into the pathobiology and treatment of negative symptoms. Eur Neuropsychopharmacol 2014; 24:800-21. [PMID: 24290531 DOI: 10.1016/j.euroneuro.2013.08.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 08/11/2013] [Accepted: 08/31/2013] [Indexed: 01/05/2023]
Abstract
Modelling negative symptoms in any animal model, particularly in mice mutant for genes related to schizophrenia, is complicated by the absence of the following key elements that might assist in developing validation criteria: clinical clarity surrounding this symptom constellation; any clear association between negative symptoms and pathological signature(s) in the brain; and therapeutic strategies with material clinical efficacy against these symptoms. In this review, the application of mutant mouse models to the study of negative symptoms is subjected to critical evaluation, focussing on the following challenges: (a) conceptual issues relating to negative symptoms and their evaluation in mutant models; (b) measurement of negative symptoms in mice, in terms of social behaviour, motivational deficits/avolition and anhedonia; (c) studies in mutants with disruption of genes either regulating aspects of neurotransmission implicated in schizophrenia or associated with risk for psychotic illness; (d) the disaggregation of behavioural phenotypes into underlying pathobiological processes, as a key to the development of new therapeutic strategies for negative symptoms. Advances in genetic and molecular technologies are facilitating these processes, such that more accurate models of putative schizophrenia-linked genetic abnormalities are becoming feasible. This progress in terms of mimicking the genetic contribution to distinct domains of psychopathology associated with psychotic illness must be matched by advances in conceptual/clinical relevance and sensitivity/specificity of phenotypic assessments at the level of behaviour.
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Schaevitz LR, Berger-Sweeney JE. Gene-Environment Interactions and Epigenetic Pathways in Autism: The Importance of One-Carbon Metabolism. ILAR J 2012; 53:322-40. [DOI: 10.1093/ilar.53.3-4.322] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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12
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Schaevitz LR, Picker JD, Rana J, Kolodny NH, Shane B, Berger-Sweeney JE, Coyle JT. Glutamate carboxypeptidase II and folate deficiencies result in reciprocal protection against cognitive and social deficits in mice: implications for neurodevelopmental disorders. Dev Neurobiol 2012; 72:891-905. [PMID: 22076974 DOI: 10.1002/dneu.21000] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Interactions between genetic and environmental risk factors underlie a number of neuropsychiatric disorders, including schizophrenia (SZ) and autism (AD). Due to the complexity and multitude of the genetic and environmental factors attributed to these disorders, recent research strategies focus on elucidating the common molecular pathways through which these multiple risk factors may function. In this study, we examine the combined effects of a haplo-insufficiency of glutamate carboxypeptidase II (GCPII) and dietary folic acid deficiency. In addition to serving as a neuropeptidase, GCPII catalyzes the absorption of folate. GCPII and folate depletion interact within the one-carbon metabolic pathway and/or of modulate the glutamatergic system. Four groups of mice were tested: wild-type, GCPII hypomorphs, and wild-types and GCPII hypomorphs both fed a folate deficient diet. Due to sex differences in the prevalence of SZ and AD, both male and female mice were assessed on a number of behavioral tasks including locomotor activity, rotorod, social interaction, prepulse inhibition, and spatial memory. Wild-type mice of both sexes fed a folic acid deficient diet showed motor coordination impairments and cognitive deficits, while social interactions were decreased only in males. GCPII mutant mice of both sexes also exhibited reduced social propensities. In contrast, all folate-depleted GCPII hypomorphs performed similarly to untreated wild-type mice, suggesting that reduced GCPII expression and folate deficiency are mutually protective. Analyses of folate and neurometabolite levels associated with glutamatergic function suggest several potential mechanisms through which GCPII and folate may be interacting to create this protective effect.
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Affiliation(s)
- Laura R Schaevitz
- Department of Biology, Tufts University, Medford, Massachusetts 02155, USA
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13
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Xie H, Guo J, Wang J, Wang F, Zhao H, Liu C, Wang L, Lu X, Wu L, Bao Y, Zou J, Zhang T, Niu B. Glutamate carboxypeptidase II gene polymorphisms and neural tube defects in a high-risk Chinese population. Metab Brain Dis 2012; 27:59-65. [PMID: 22124883 DOI: 10.1007/s11011-011-9272-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 11/08/2011] [Indexed: 11/27/2022]
Abstract
Glutamate carboxypeptidase II (GCPII) catalyzes the hydrolysis of N-acetylaspartylglutamate into N-acetylaspartate and glutamate in the brain. Animal experiments suggested that GCPII plays an essential role in early embryonic development. Previous studies provided conflicting results on the effect of the GCPII rs61886492 C>T (or 1561C>T) polymorphism on NTDs. In the Lvliang area of Shanxi province, where the incidence of NTDs is the highest in China, a case-control study was conducted to investigate possible association between the GCPII rs61886492 and rs202676 polymorphisms and NTD risk. Results indicated all the case and control samples displayed the rs61886492 GG genotype. Although no significant differences in rs202676 genotype or allele frequencies were found between the NTD and control groups, the combined AG+GG genotype group was significantly associated with anencephaly (p = 0.03, OR = 2.11, 95% CI, 1.11-4.01), but not with spina bifida or encephalocele. Overall, the rs202676 A>G polymorphism is a potential risk factor for anencephaly. The results of this study suggest that phenotypic heterogeneity may exist among NTDs in this Chinese population.
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Affiliation(s)
- Hua Xie
- Capital Institute of Pediatrics, Beijing 100020, People's Republic of China
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Powell SB, Weber M, Geyer MA. Genetic models of sensorimotor gating: relevance to neuropsychiatric disorders. Curr Top Behav Neurosci 2012; 12:251-318. [PMID: 22367921 PMCID: PMC3357439 DOI: 10.1007/7854_2011_195] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Sensorimotor gating, or the ability of a sensory event to suppress a motor response, can be measured operationally via prepulse inhibition (PPI) of the startle response. PPI is deficient in schizophrenia patients as well as other neuropsychiatric disorders, can be measured across species, and has been used widely as a translational tool in preclinical neuropharmacological and genetic research. First developed to assess drug effects in pharmacological and developmental models, PPI has become one of the standard behavioral measures in genetic models of schizophrenia and other neuropsychiatric disorders that exhibit PPI deficits. In this chapter we review the literature on genetic models of sensorimotor gating and discuss the utility of PPI as a tool in phenotyping mutant mouse models. We highlight the approaches to genetic mouse models of neuropsychiatric disease, discuss some of the important caveats to these approaches, and provide a comprehensive table covering the more recent genetic models that have evaluated PPI.
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Affiliation(s)
- Susan B. Powell
- Department of Psychiatry, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0804, USA
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Martin Weber
- Department of Neuroscience, Genentech Inc, 1 DNA Way, South San Francisco, CA 94080-4990, USA
| | - Mark A. Geyer
- Department of Psychiatry, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0804, USA
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
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Neale JH, Olszewski RT, Zuo D, Janczura KJ, Profaci CP, Lavin KM, Madore JC, Bzdega T. Advances in understanding the peptide neurotransmitter NAAG and appearance of a new member of the NAAG neuropeptide family. J Neurochem 2011; 118:490-8. [PMID: 21644997 DOI: 10.1111/j.1471-4159.2011.07338.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A substantial body of data was reported between 1984 and 2000 demonstrating that the neuropeptide N-acetylaspartylglutamate (NAAG) not only functions as a neurotransmitter but also is the third most prevalent transmitter in the mammalian nervous system behind glutamate and GABA. By 2005, this conclusion was validated further through a series of studies in vivo and in vitro. The primary enzyme responsible for the inactivation of NAAG following its synaptic release had been cloned, characterized and knocked out. Potent inhibitors of this enzyme were developed and their efficacy has been extensively studied in a series of animal models of clinical conditions, including stroke, peripheral neuropathy, traumatic brain injury, inflammatory and neuropathic pain, cocaine addiction, and schizophrenia. Considerable progress also has been made in defining further the mechanism of action of these peptidase inhibitors in elevating synaptic levels of NAAG with the consequent inhibition of transmitter release via the activation of pre-synaptic metabotropic glutamate receptor 3 by this peptide. Very recent discoveries include identification of two different nervous system enzymes that mediate the synthesis of NAAG from N-acetylaspartate and glutamate and the finding that one of these enzymes also mediates the synthesis of a second member of the NAAG family of neuropeptides, N-acetylaspartylglutamylglutamate.
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Affiliation(s)
- Joseph H Neale
- Department of Biology, Georgetown University, Washington, District of Columbia 20057, USA.
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Abstract
The possible role of the CB(2) receptor (CB(2)r) in psychiatric disorders has been considered. Several animal models use knockout (KO) mice that display schizophrenia-like behaviors and this study evaluated the role of CB(2)r in the regulation of such behaviors. Mice lacking the CB(2)r (CB(2)KO) were challenged in open field, light-dark box, elevated plus-maze, tail suspension, step down inhibitory avoidance, and pre-pulse inhibition tests (PPI). Furthermore, the effects of treatment with cocaine and risperidone were evaluated using the OF and the PPI test. Gene expression of dopamine D(2) (D(2)r), adrenergic-α(2C) (α(2C)r), serotonergic 5-HT(2A) and 5-HT(2C) receptors (5-HT(2A)r and 5-HT(2C)r) were studied by RT-PCR in brain regions related to schizophrenia. Deletion of CB(2)r decreased motor activity in the OF test, but enhanced response to acute cocaine and produced mood-related alterations, PPI deficit, and cognitive impairment. Chronic treatment with risperidone tended to impair PPI in WT mice, whereas it 'normalized' the PPI deficit in CB(2)KO mice. CB(2)KO mice presented increased D(2)r and α(2C)r gene expressions in the prefrontal cortex (PFC) and locus coeruleus (LC), decreased 5-HT(2C)r gene expression in the dorsal raphe (DR), and 5-HT(2A)r gene expression in the PFC. Chronic risperidone treatment in WT mice left α(2C)r gene expression unchanged, decreased D(2)r gene expression (15 μg/kg), and decreased 5-HT(2C)r and 5-HT(2A)r in PFC and DR. In CB(2)KO, the gene expression of D(2)r in the PFC, of α(2C)r in the LC, and of 5-HT(2C)r and 5-HT(2A)r in PFC was reduced; 5-HT(2C)r and 5-HT(2A)r gene expressions in DR were increased after treatment with risperidone. These results suggest that deletion of CB(2)r has a relation with schizophrenia-like behaviors. Pharmacological manipulation of CB(2)r may merit further study as a potential therapeutic target for the treatment of schizophrenia-related disorders.
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Takatsu Y, Fujita Y, Tsukamoto T, Slusher BS, Hashimoto K. Orally active glutamate carboxypeptidase II inhibitor 2-MPPA attenuates dizocilpine-induced prepulse inhibition deficits in mice. Brain Res 2011; 1371:82-6. [DOI: 10.1016/j.brainres.2010.11.048] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2010] [Revised: 11/10/2010] [Accepted: 11/10/2010] [Indexed: 11/26/2022]
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Discordant behavioral effects of psychotomimetic drugs in mice with altered NMDA receptor function. Psychopharmacology (Berl) 2011; 213:143-53. [PMID: 20865248 PMCID: PMC4818544 DOI: 10.1007/s00213-010-2023-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Accepted: 09/06/2010] [Indexed: 01/08/2023]
Abstract
RATIONALE Enhancement of N-methyl-D: -aspartate receptor (NMDAR) activity through its glycine modulatory site (GMS) is a novel therapeutic approach in schizophrenia. Brain concentrations of endogenous GMS agonist D: -serine and antagonist N-acetyl-aspartylglutamate are regulated by serine racemase (SR) and glutamic acid decarboxylase 2 (GCP2), respectively. Using mice genetically, under-expressing these enzymes may clarify the role of NMDAR-mediated neurotransmission in schizophrenia. OBJECTIVES We investigated the behavioral effects of two psychotomimetic drugs, the noncompetitive NMDAR antagonist, phencyclidine (PCP; 0, 1.0, 3.0, or 6.0 mg/kg), and the indirect dopamine receptor agonist, amphetamine (AMPH; 0, 1.0, 2.0, or 4.0 mg/kg), in SR -/- and GCP2 -/+ mice. Outcome measures were locomotor activity and prepulse inhibition (PPI) of the acoustic startle reflex. Acute effects of an exogenous GMS antagonist, gavestinel (0, 3.0, or 10.0 mg/kg), on PCP-induced behaviors were examined in wild-type mice for comparison to the mutants with reduced GMS activity. RESULTS PCP-induced hyperactivity was increased in GCP2 -/+ mice, and PCP-enhanced startle reactivity was increased in SR -/- mice. PCP disruption of PPI was unaffected in either mutant. In contrast, gavestinel attenuated PCP-induced PPI disruption without effect on baseline PPI or locomotor activity. AMPH effects were similar to controls in both mutant strains. CONCLUSIONS The results of the PCP experiments demonstrate that convergence of pharmacological and genetic manipulations at NMDARs may confound the predictive validity of these preclinical assays for the effects of GMS activation in schizophrenia. The AMPH data provide additional evidence that hyperdopaminergia in schizophrenia may be distinct from NMDAR hypofunction.
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O'Tuathaigh CMP, Kirby BP, Moran PM, Waddington JL. Mutant mouse models: genotype-phenotype relationships to negative symptoms in schizophrenia. Schizophr Bull 2010; 36:271-88. [PMID: 19934211 PMCID: PMC2833123 DOI: 10.1093/schbul/sbp125] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Negative symptoms encompass diminution in emotional expression and motivation, some of which relate to human attributes that may not be accessible readily in animals. Additionally, their refractoriness to treatment precludes therapeutic validation of putative models. This review considers critically the application of mutant mouse models to the study of the pathobiology of negative symptoms. It focuses on 4 main approaches: genes related to the pathobiology of schizophrenia, genes associated with risk for schizophrenia, neurodevelopmental-synaptic genes, and variant approaches from other areas of neurobiology. Despite rapid advances over the past several years, it is clear that we continue to face substantive challenges in applying mutant models to better understand the pathobiology of negative symptoms: the majority of evidence relates to impairments in social behavior, with only limited data relating to anhedonia and negligible data concerning avolition and other features; even for the most widely examined feature, social behavior, studies have used diverse assessments thereof; modelling must proceed in cognizance of increasing evidence that genes and pathobiologies implicated in schizophrenia overlap with other psychotic disorders, particularly bipolar disorder. Despite the caveats and challenges, several mutant lines evidence a phenotype for at least one index of social behavior. Though this may suggest superficially some shared relationship to negative symptoms, it is not yet possible to specify either the scope or the pathobiology of that relationship for any given gene. The breadth and depth of ongoing studies in mutants hold the prospect of addressing these shortcomings.
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Affiliation(s)
- Colm M. P. O'Tuathaigh
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, St Stephen's Green, Dublin 2, Ireland,To whom correspondence should be addressed; tel: +353-1-402-2377, fax: +353-1-402-2453, e-mail:
| | - Brian P. Kirby
- School of Pharmacy, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Paula M. Moran
- School of Psychology, University of Nottingham, Nottingham, UK
| | - John L. Waddington
- Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, St Stephen's Green, Dublin 2, Ireland
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Schaevitz LR, Moriuchi JM, Nag N, Mellot TJ, Berger-Sweeney J. Cognitive and social functions and growth factors in a mouse model of Rett syndrome. Physiol Behav 2010; 100:255-63. [PMID: 20045424 DOI: 10.1016/j.physbeh.2009.12.025] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 12/18/2009] [Accepted: 12/22/2009] [Indexed: 11/18/2022]
Abstract
Rett syndrome (RTT) is an autism-spectrum disorder caused by mutations in the X-linked gene encoding methyl-CpG-binding protein 2 (MeCP2). Abnormalities in social behavior, stereotyped movements, and restricted interests are common features in both RTT and classic autism. While mouse models of both RTT and autism exist, social behaviors have not been explored extensively in mouse models of RTT. Here, we report cognitive and social abnormalities in Mecp2(1lox) null mice, an animal model of RTT. The null mice show severe deficits in short- and long-term object recognition memories, reminiscent of the severe cognitive deficits seen in RTT girls. Social behavior, however, is abnormal in that the null mice spend more time in contact with stranger mice than do wildtype controls. These findings are consistent with reports of increased reciprocal social interaction in RTT girls relative to classic autism. We also report here that the levels of the neurotrophins brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), and nerve growth factor (NGF) are decreased in the hippocampus of the null mice, and discuss how this may provide an underlying mechanism for both the cognitive deficits and the increased motivation for social contact observed in the Mecp2(1lox) null mice. These studies support a differential etiology between RTT and autism, particularly with respect to sociability deficits.
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Affiliation(s)
- Laura R Schaevitz
- Department of Biological Sciences, Wellesley College, Wellesley MA 02481, United States
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Ramsey AJ. NR1 knockdown mice as a representative model of the glutamate hypothesis of schizophrenia. PROGRESS IN BRAIN RESEARCH 2009; 179:51-8. [PMID: 20302817 DOI: 10.1016/s0079-6123(09)17906-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
N-methyl d-aspartate (NMDA) receptor subunit NR1 knockdown (NR1-KD) mice have a global reduction of NMDA receptors, enabling their use as a genetic model to study the role of NMDA receptors in the pathophysiology of schizophrenia. This targeted mutation results in a spectrum of altered behaviors that are similar to those induced by NMDA receptor antagonists, which have long been used to model schizophrenia in animals. NR1-KD mice serve as a complementary tool to pharmacological models, providing insight into the consequences of sustained NMDA receptor dysfunction in early brain development and throughout the life of the animal. Though in many respects the phenotype of NR1-KD mice mimics that of acute NMDA receptor antagonism, there are also notable differences. In this chapter we highlight some of the molecular, behavioral, and neurophysiological phenotypes of NR1-KD mice and compare these to pharmacological models of NMDA receptor dysfunction. Through the study of these models, our improved understanding of how the brain adapts to persistent NMDA receptor hypofunction may eventually suggest new therapeutic strategies for schizophrenia.
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Affiliation(s)
- Amy J Ramsey
- University of Toronto, Department of Pharmacology and Toxicology, Toronto, ON, Canada.
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